A vintage wine is one made from grapes that were all, or primarily, grown in a single specified year, and are accordingly dated as such. In the United States for a wine to be vintage dated (and labeled with a country of origin or AVA, such as "Napa Valley" or "New Zealand") it must contain at least 95% of its volume from wines harvested in that year. If a wine is not labeled with a country of origin or AVA, such as "Napa County", it must contain at least 85% of its volume from wines harvested in that year. Many wines, particularly good quality red table wines, can improve in flavor with age if properly stored. Consequently, it is not uncommon for wine enthusiasts and traders to save bottles of an especially good vintage wine for future consumption. Most countries allow a vintage wine to include a portion of wine that is not from the labeled vintage. Recent research suggests vintage year may not be as significant to wine quality as currently thought.
For some types of wine, the best-quality grapes and the most care in wine-making are employed on vintage wines and they are therefore more expensive than non-vintage wines. Whilst vintage wines are generally made in a single batch so that each and every bottle will have a similar taste, climatic factors can have a dramatic impact on the character of a wine to the extent that different vintages from the same vineyard can vary dramatically in flavor and quality. Thus, vintage wines are produced to be individually characteristic of the vintage and to serve as the flagship wines of the producer. Non-vintage wines, however, are blended from a number of vintages for consistency, a process which allows wine makers to keep a reliable market image and also maintain sales even in bad vintage years. Superior vintages, from reputable producers and regions, will often fetch much higher prices than their average vintages. Some vintage wines are only made in better-than-average years.